The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Ikuo Kashiwakura - One of the best experts on this subject based on the ideXlab platform.
-
Maternal/Neonatal Obstetric Factors
2016Co-Authors: Atsuko Omori, Takako Chiba, Ikuo KashiwakuraAbstract:Cord blood/Hematopoietic progenitor cells/Obstetric factors/Radiosensitivity. Hematopoietic stem/progenitor cells (HSPCs) in placental/umbilical cord blood (CB), which is neo-natal peripheral blood, have increasingly been used for hematopoietic stem cell transplantations. It is likely HSPCs are sensitive to extracellular oxidative stresses, such as ionizing radiation and redox-directed che-motherapeutic agents. However, the radiosensitivity of HSPCs and neonatal hematopoietic system remains unclear. This study investigated the potential relationship between the radiosensitivity of HSPCs in CB, which was obtained from singleton and full-term deliveries, and maternal/neonatal obstetric factors. Freshly prepared CB CD34+ cells exposed to 2 Gy X-irradiation were assayed for hematopoietic progeni-tor cells such as colony-forming unit-granulocyte-macrophage (CFU-GM), burst-forming unit-erythroid (BFU-E), colony-forming unit-granulocyte-erythroid-macrophage-megakaryocyte (CFU-Mix), and colony-forming unit-megakaryocyte (CFU-Meg). As a result, the neonatal weight, placental weight, CB volume, total low-density (LD) cells, and CD34+ cells showed mutually significant positive correlations. The CB volume and total LD cells showed a significant reverse correlation with the surviving fraction of CFU-Meg. The surviving fraction of CFU-GM in spring (March–May) was significantly higher than that in autumn (September–November). The surviving fraction of CFU-Meg in the spring was significantly lower than that in the autumn. Male neonates showed a significantly higher surviving fraction of CFU-GM than female neonates. Contrarily, females showed a significantly higher surviving fraction of CFU-Meg than males. The present results suggest that the obstetric factors, such as the season of birth and neonatal gen-der, influence the radiosensitivity of neonatal hematopoiesis
-
Relationship Between Radiosensitivity of Human Neonatal Hematopoietic Stem/Progenitor Cells and Individual Maternal/Neonatal Obstetric Factors
Journal of radiation research, 2010Co-Authors: Atsuko Omori, Takako Chiba, Ikuo KashiwakuraAbstract:Hematopoietic stem cells (HSCs) in placental/umbilical cord blood (CB), which is neonatal peripheral blood, have increasingly been used for hematopoietic stem cell transplantations. It is likely HSCs are sensitive to extracellular oxidative stresses, such as ionizing radiation and redox-directed chemotherapeutic agents. However, the radiosensitivity of HSPCs and neonatal hematopoietic system remains unclear. This study investigated the potential relationship between the radiosensitivity of hematopoietic stem/progenitor cells (HSPCs) in CB, which was obtained from singleton and full-term deliveries, and maternal/neonatal obstetric factors. Freshly prepared CB CD34+ cells exposed to 2 Gy X-irradiation were assayed for hematopoietic progenitor cells such as colony-forming unit-granulocyte-macrophage (CFU-GM), burst-forming unit-erythroid (BFU-E), colony-forming unit-granulocyte-erythroid-macrophage-megakaryocyte (CFU-Mix), and colony-forming unit-megakaryocyte (CFU-Meg). As a result, the neonatal weight, placental weight, CB volume, total low-density (LD) cells, and CD34+ cells showed mutually significant positive correlations. The CB volume and total LD cells showed a significant reverse correlation with the surviving fraction of CFU-Meg. The surviving fraction of CFU-GM in spring (March–May) was significantly higher than that in autumn (September–November). The surviving fraction of CFU-Meg in the spring was significantly lower than that in the autumn. Male neonates showed a significantly higher surviving fraction of CFU-GM than female neonates. Contrarily, females showed a significantly higher surviving fraction of CFU-Meg than males. The present results suggest that the obstetric factors, such as the season of birth and neonatal gender, influence the radiosensitivity of neonatal hematopoiesis.
-
The Effects of Heavy Ion Particles on Human Megakaryocytopoiesis and Thrombopoiesis.
Blood, 2006Co-Authors: Ikuo Kashiwakura, Satoru Monzen, Kenji Takahashi, Kiyomi Eguchi-kasai, Tsutomu Toki, Yoshinao AbeAbstract:Heavy ion particles provide unique properties in radiotherapy. However, they have also been shown to pose high risks for both work at nuclear facilities and astronauts participating in space missions. In a previous study, we demonstrated that in radio-sensitive megakaryocyte progenitor cells, namely colony-forming unit megakaryocytes (CFU-Meg), a degree of X-ray-induced damage was prevented by post-treatment with several cytokines. In this study, we analyzed the effects of heavy ion particles on megakaryocytopoiesis and thrombopoiesis. The CD34 + CFU-Meg were isolated from human placental and umbilical cord blood using a magnetic isolation kit and then were exposed to a carbon ion beam (LET=50 KeV/mm). They were cultured in a serum free medium supplemented with a thrombopoietin (TPO) alone or a combination of TPO plus other cytokines including stem cell factor, interleukin-3 (IL-3) and Flt3-ligand. The number of CFU-Meg was calculated by a plasma clot technique. The differentiation into megakaryocytes (CD41 + ) and the release of platelets (CD42a + ) in a liquid culture were both analyzed by flow cytometry. The increase of gamma-H2AX, a marker of DNA double-strand breaks (DSBs) was also detected by flow cytometry. The sensitivity of CFU-Meg to a carbon ion beam was found to be extremely high and could not be lowered by any type of cytokines unlike X-rays. However, treatment with TPO plus IL-3 potentially induced megakaryocytopoiesis and thrombopoiesis at 14 days after the exposure to a carbon ion beam at 2 Gy. The cytokine treatment enhanced the induction of gamma-H2AX in X-ray-irradiated CD34 + CFU-Meg but not in a carbon ion beam-irradiated one. These results show that not only the downregulation of death signals, but also the repair of DSBs was less strongly promoted by cytokines in CFU-Meg exposed to a carbon ion beam than X-rays. Different treatments therefore are required to protect against megakaryocytopoiesis and thrombopoiesis damage by heavy ion particles.
-
The Effects of Glycosaminoglycans on Thrombopoietin-Induced Megakaryocytopoiesis.
Blood, 2006Co-Authors: Kenji Takahashi, Ikuo Kashiwakura, Tsutomu Toki, Keiichi TakagakiAbstract:Results. When used alone, none of the GAG supported the clonal growth of CFU-Meg; however, in cultures stimulated by recombinant human thrombopoietin, human hyaluron- ic acid, whale chondroitin sulfate and DS significantly enhanced such growth. In particu- lar, the addition of DS resulted in increases of about 1.3-fold, 1.6-fold and 2.0-fold in the numbers of total cells, megakaryocytes and CFU-Meg, respectively, compared with the control culture stimulated by thrombopoietin alone after 9-12 days of serum-free liquid culture. Furthermore, DS induced the generation of hyperploid megakaryocytes and pro- moted pro-platelet formation. Chemical fragmentation and desulfation of DS showed that a chain of at least 12 saccharides is required for colony-promoting activity and that the sulfate groups play an essential role. Interpretation and Conclusions. DS acts on an immature population of CD34 + cells, stim- ulates the proliferation of CFU-Meg, and enhances the terminal maturation of megakary- ocytes and thrombopoiesis. These results suggest that DS has a wide spectrum of action in promoting megakaryocytopoiesis and thrombopoiesis.
-
Effects of liquid crystal-related compounds on human megakaryocytopoiesis and thrombopoiesis
Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan, 2006Co-Authors: Rie Terasawa, Ikuo Kashiwakura, Atsushi YoshizawaAbstract:In the present study, the effects of liquid crystal-related compounds on the megakaryocytopoiesis and thrombopoiesis were evaluated in vitro using CD34+ cells prepared from human placental and umbilical cord blood (CB). About 20 kinds of compounds were tested for their effects on the clonal growth of CB CD34+ megakaryocytic progenitor cells (CFU-Meg) in plasma clot culture. The compounds, dissolved in DMSO, were added to the cultures within a concentration range of 10-100 nM. When used alone, none of the compounds supported the clonal growth of CFU-Meg. However, when thrombopoietin (TPO) was used as a growth factor, three compounds increased CFU-Meg clonal growth significantly, producing approximately 1.3-1.4 fold increases in the total number of megakaryocyte colonies in comparison with the control. These compounds promoted mainly mature CFU-Meg-derived small colonies, suggesting that their target is relatively mature CFU-Meg. These effective compounds were examined in liquid culture supplemented with TPO alone for 14 days. Although there was no evident promotion of the total number of cells harvested from the culture, two compounds suppressed cell growth significantly. Only one compound enhanced the generation of CFU-Meg in the harvested cells. Although these results do not indicate a strong correlation between the chemical structure of each compound and biological effectiveness, the incorporation of phenylpyridine and phenylpyrimidine and binding of a hydroxyl residue into the structure may play an important role in the activity. Thus, liquid crystal-related compounds whose biological action was previously unknown have been shown to act as regulators of hematopoiesis.
Yoshinari Takagi - One of the best experts on this subject based on the ideXlab platform.
-
the effects of glycosaminoglycans on thrombopoietin induced megakaryocytopoiesis
Haematologica, 2006Co-Authors: Ikuo Kashiwakura, Tsuneo A. Takahashi, Yoshinari Takagi, Tomoe Teramachi, Ikuko Kakizaki, Keiichi TakagakiAbstract:BACKGROUND AND OBJECTIVES: The extracellular matrix plays an essential role in normal hematopoiesis. Proteoglycans and glycosaminoglycans (GAG) are major components of the matrix. In this study, the effects of various GAG on the proliferation and differentiation of CD34+ megakaryocytic progenitor cells (CFU-Meg) were evaluated in vitro. DESIGN AND METHODS: CD34+ cells were highly purified from steady-state human peripheral blood. The GAG tested were hyaluronic acid (from humans, pigs and roosters), keratan sulfate, heparan sulfate, chondroitin sulfate (from whale, shark or squid cartilage) and dermatan sulfate (DS). RESULTS: When used alone, none of the GAG supported the clonal growth of CFU-Meg; however, in cultures stimulated by recombinant human thrombopoietin, human hyaluronic acid, whale chondroitin sulfate and DS significantly enhanced such growth. In particular, the addition of DS resulted in increases of about 1.3-fold, 1.6-fold and 2.0-fold in the numbers of total cells, megakaryocytes and CFU-Meg, respectively, compared with the control culture stimulated by thrombopoietin alone after 9-12 days of serum-free liquid culture. Furthermore, DS induced the generation of hyperploid megakaryocytes and promoted pro-platelet formation. Chemical fragmentation and desulfation of DS showed that a chain of at least 12 saccharides is required for colony-promoting activity and that the sulfate groups play an essential role. INTERPRETATION AND CONCLUSIONS: DS acts on an immature population of CD34+ cells, stimulates the proliferation of CFU-Meg, and enhances the terminal maturation of megakaryocytes and thrombopoiesis. These results suggest that DS has a wide spectrum of action in promoting megakaryocytopoiesis and thrombopoiesis.
-
Effects of amifostine on the proliferation and differentiation of megakaryocytic progenitor cells
European Journal of Pharmacology, 2002Co-Authors: Ikuo Kashiwakura, Miho Murakami, Yukitoshi Hayase, Tsuneo A. Takahashi, Mikinori Kuwabara, Osamu Inanami, Yoshinari TakagiAbstract:This study investigated the effects of amifostine, a clinically usable radioprotector or chemoprotector, on the proliferation and differentiation of normal and X-irradiated cluster of differentiation 34 positive (CD34+) megakaryocytic progenitor cells (colony-forming unit in megakaryocytes, CFU-Meg) from human placental and umbilical cord blood (CB) in vitro. Amifostine significantly accelerated megakaryocyte colony formation in a plasma clot culture supplemented with recombinant human thrombopoietin because of an increase in immature CFU-Meg-derived large megakaryocyte colony formation. An analysis of the cells that were harvested from the culture showed that amifostine induced a 70- and an 83-fold increase in the total cell and CFU-Meg numbers, respectively, and produced hyperploid megakaryocytes of more than 8 N ploidy. The radioprotective effect of amifostine on the clonal growth of X-irradiated CD34+ CFU-Meg was observed by treatment before or after irradiation. These findings suggest that the action of amifostine extends from immature CFU-Meg to the terminal differentiation of megakaryopoiesis, and its radioprotective effect is shown in megakaryopoiesis and thrombopoiesis.
-
Effects of glycosaminoglycans on the in vitro colony formation of CD34+ megakaryocytic progenitor cells in human placental/umbilical cord blood
Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan, 2001Co-Authors: Tomoe Teramachi, Ikuo Kashiwakura, Tsuneo A. Takahashi, Yoshinari TakagiAbstract:The in vitro effect of various glycosaminoglycans (GAGs) on the clonal growth of CD34+ megakaryocytic progenitor cells (CFU-Megs) isolated from human placental/umbilical cord blood (CB) was evaluated in human plasma containing semisolid culture stimulated by recombinant human thrombopoietin (TPO). The GAGs, including hyaluronic acid from human umbilical cords (HA-h), pig skins (HA-p) and rooster combs (HA-r), or keratan sulfate (KS), various chondroitin sulfates (CS-A, B, C, D, E), and heparan sulfate (HS), were tested. Each GAG alone did not affect the clonal growth of CFU-Meg. In the presence of TPO, adding of HA-p or HS (100 micrograms/ml) resulted in an approximately 1.3-fold increase, in the total number of colonies, due to an increase in large megakaryocyte colonies. In contrast, CS-E led to a marked decrease in CFU-Meg growth. At the end of the culture, the total number of cells increased 3.0-fold of the initial value of the control, but adding HA-p or HS showed an approximately 9.1-fold or 18.3-fold increase. Similarly, the total number of CFU-Meg detected in the harvested cells increased to 4.8-fold of the initial value, while, an approximately 18.3-fold or 38.8-fold increase was observed in the culture containing HA-p or HS, respectively. Flow cytometric analysis of the harvested cells showed no significant difference in the expression of surface antigens and DNA ploidy distribution of megakaryocytes between the control and GAG treatments. These results suggest that HA-p and HS promote the proliferation of immature CB CD34+ CFU-Meg in the presence of TPO.
-
Expansion of megakaryocyte progenitors from cryopreserved leukocyte concentrates of human placental and umbilical cord blood in short-term liquid culture
Cytotherapy, 2001Co-Authors: N. Sasayama, Miho Murakami, Yoshinari Takagi, I. Kashiwakura, Y. Tokushima, S. Wada, Y. Hayase, Tsuneo A. TakahashiAbstract:Long-term severe thrombocytopenia following human placental and umbilical cord blood (CB) transplantation is a significant clinical problem. We studied the ex vivo expansion of megakaryocytic progenitor cells (CFU-Meg) from cryopreserved/thawed leukocyte concentrates (LC) of CB prepared by the Tokyo Cord Blood Bank protocol. The LC cells were cultured in serum-free culture medium supplemented with a combination of early-acting cytokines including thrombopoietin (TPO), flt3-ligand (FL), and stem cell factor (SCF). Combination of TPO plus FL, TPO plus SCF, and all of these cytokines together resulted in 8.9-, 7.7-, and 8.4-fold increases in CFU-Meg, respectively, by Day 5 of culture. Our results showed that this simple expansion strategy has the potential for expanding CFU-Meg from cryopreserved/thawed LC cells from CB.
-
Effect of murine kidney extracts on the proliferation of hematopoietic progenitor cells in human umbilical cord blood.
Biological & pharmaceutical bulletin, 2000Co-Authors: Miho Murakami, Ikuo Kashiwakura, Yukitoshi Hayase, Tsuneo A. Takahashi, Yoshinari TakagiAbstract:We examined the effect of murine kidney extract (MKE) on the clonal growth of highly purified CD34+ hematopoietic progenitor cells from human umbilical cord blood. MKE did not affect the total number of colonies of erythroid burst-forming units (BFU-E), granulocyte-macrophage colony-forming units (CFU-GM) or granulocyte-erythroid-macrophage-megakaryocyte colony-forming units (CFU-Mix/CFU-GEMM) in a methyl-cellulose culture with exogenous recombinant human granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, interleukin-3, stem cell factor and erythropoietin. MKE significantly increased the proportion of BFU-E- or CFU-Mix-derived colonies, and suppressed the formation CFU-GM-derived colonies depending on the MKE dose. However, because of an increase in small megakaryocyte colonies derived from mature CFU-Meg MKE increased by approximately 40% the growth of megakaryocyte colony-forming units (CFU-Meg) in plasma clot culture stimulated by recombinant human thrombopoietin. Also MKE promoted an increase in hyperploid megakaryocytes, suggesting that the active factor(s) in MKE acts on the mature CFU-Meg and promotes the maturation of megakaryocytes. Gel-filtration high performance liquid chromatography of MKE showed that the promoting factor(s) in MKE was approximately 45 kDa. These results indicate that the factor(s) detected in MKE influence human hematopoiesis in vitro, especially thrombopoiesis.
Tsuneo A. Takahashi - One of the best experts on this subject based on the ideXlab platform.
-
the effects of glycosaminoglycans on thrombopoietin induced megakaryocytopoiesis
Haematologica, 2006Co-Authors: Ikuo Kashiwakura, Tsuneo A. Takahashi, Yoshinari Takagi, Tomoe Teramachi, Ikuko Kakizaki, Keiichi TakagakiAbstract:BACKGROUND AND OBJECTIVES: The extracellular matrix plays an essential role in normal hematopoiesis. Proteoglycans and glycosaminoglycans (GAG) are major components of the matrix. In this study, the effects of various GAG on the proliferation and differentiation of CD34+ megakaryocytic progenitor cells (CFU-Meg) were evaluated in vitro. DESIGN AND METHODS: CD34+ cells were highly purified from steady-state human peripheral blood. The GAG tested were hyaluronic acid (from humans, pigs and roosters), keratan sulfate, heparan sulfate, chondroitin sulfate (from whale, shark or squid cartilage) and dermatan sulfate (DS). RESULTS: When used alone, none of the GAG supported the clonal growth of CFU-Meg; however, in cultures stimulated by recombinant human thrombopoietin, human hyaluronic acid, whale chondroitin sulfate and DS significantly enhanced such growth. In particular, the addition of DS resulted in increases of about 1.3-fold, 1.6-fold and 2.0-fold in the numbers of total cells, megakaryocytes and CFU-Meg, respectively, compared with the control culture stimulated by thrombopoietin alone after 9-12 days of serum-free liquid culture. Furthermore, DS induced the generation of hyperploid megakaryocytes and promoted pro-platelet formation. Chemical fragmentation and desulfation of DS showed that a chain of at least 12 saccharides is required for colony-promoting activity and that the sulfate groups play an essential role. INTERPRETATION AND CONCLUSIONS: DS acts on an immature population of CD34+ cells, stimulates the proliferation of CFU-Meg, and enhances the terminal maturation of megakaryocytes and thrombopoiesis. These results suggest that DS has a wide spectrum of action in promoting megakaryocytopoiesis and thrombopoiesis.
-
Different radiosensitive megakaryocytic progenitor cells exist in steady-state human peripheral blood
Radiation research, 2005Co-Authors: Ikuo Kashiwakura, Yoshinao Abe, Tsuneo A. Takahashi, Osamu Inanami, Mikinori KuwabaraAbstract:Abstract Kashiwakura, I., Inanami, O., Abe, Y., Takahashi, T. A. and Kuwabara, M. Different Radiosensitive Megakaryocytic Progenitor Cells Exist in Steady-State Human Peripheral Blood. Radiat. Res. 164, 10–16 (2005). CD34 antigen is a novel marker for human hematopoietic stem/progenitor cells. In the present study, two cell fractions, CD34low and CD34high, were prepared from steady-state human peripheral blood on the basis of CD34 antigen expression. The colony-forming unit megakaryocytes (CFU-Meg) contained in each cell fraction were compared for X-radiation sensitivity and cytokine action. The content of CD34+CD45+ cells in the CD34low and CD34high cell fractions was 74.8% and 88.8%, respectively, and the frequency of thrombopoietin (TPO)-supported CFU-Meg in the CD34low cell fraction was 1.9 times higher than that in CD34high. The CFU-Meg in CD34high were more radiosensitive than those in CD34low, indicating that steady-state human peripheral blood contains different types of CFU-Meg. However, no signi...
-
Effects of amifostine on the proliferation and differentiation of megakaryocytic progenitor cells
European Journal of Pharmacology, 2002Co-Authors: Ikuo Kashiwakura, Miho Murakami, Yukitoshi Hayase, Tsuneo A. Takahashi, Mikinori Kuwabara, Osamu Inanami, Yoshinari TakagiAbstract:This study investigated the effects of amifostine, a clinically usable radioprotector or chemoprotector, on the proliferation and differentiation of normal and X-irradiated cluster of differentiation 34 positive (CD34+) megakaryocytic progenitor cells (colony-forming unit in megakaryocytes, CFU-Meg) from human placental and umbilical cord blood (CB) in vitro. Amifostine significantly accelerated megakaryocyte colony formation in a plasma clot culture supplemented with recombinant human thrombopoietin because of an increase in immature CFU-Meg-derived large megakaryocyte colony formation. An analysis of the cells that were harvested from the culture showed that amifostine induced a 70- and an 83-fold increase in the total cell and CFU-Meg numbers, respectively, and produced hyperploid megakaryocytes of more than 8 N ploidy. The radioprotective effect of amifostine on the clonal growth of X-irradiated CD34+ CFU-Meg was observed by treatment before or after irradiation. These findings suggest that the action of amifostine extends from immature CFU-Meg to the terminal differentiation of megakaryopoiesis, and its radioprotective effect is shown in megakaryopoiesis and thrombopoiesis.
-
Effects of glycosaminoglycans on the in vitro colony formation of CD34+ megakaryocytic progenitor cells in human placental/umbilical cord blood
Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan, 2001Co-Authors: Tomoe Teramachi, Ikuo Kashiwakura, Tsuneo A. Takahashi, Yoshinari TakagiAbstract:The in vitro effect of various glycosaminoglycans (GAGs) on the clonal growth of CD34+ megakaryocytic progenitor cells (CFU-Megs) isolated from human placental/umbilical cord blood (CB) was evaluated in human plasma containing semisolid culture stimulated by recombinant human thrombopoietin (TPO). The GAGs, including hyaluronic acid from human umbilical cords (HA-h), pig skins (HA-p) and rooster combs (HA-r), or keratan sulfate (KS), various chondroitin sulfates (CS-A, B, C, D, E), and heparan sulfate (HS), were tested. Each GAG alone did not affect the clonal growth of CFU-Meg. In the presence of TPO, adding of HA-p or HS (100 micrograms/ml) resulted in an approximately 1.3-fold increase, in the total number of colonies, due to an increase in large megakaryocyte colonies. In contrast, CS-E led to a marked decrease in CFU-Meg growth. At the end of the culture, the total number of cells increased 3.0-fold of the initial value of the control, but adding HA-p or HS showed an approximately 9.1-fold or 18.3-fold increase. Similarly, the total number of CFU-Meg detected in the harvested cells increased to 4.8-fold of the initial value, while, an approximately 18.3-fold or 38.8-fold increase was observed in the culture containing HA-p or HS, respectively. Flow cytometric analysis of the harvested cells showed no significant difference in the expression of surface antigens and DNA ploidy distribution of megakaryocytes between the control and GAG treatments. These results suggest that HA-p and HS promote the proliferation of immature CB CD34+ CFU-Meg in the presence of TPO.
-
Expansion of megakaryocyte progenitors from cryopreserved leukocyte concentrates of human placental and umbilical cord blood in short-term liquid culture
Cytotherapy, 2001Co-Authors: N. Sasayama, Miho Murakami, Yoshinari Takagi, I. Kashiwakura, Y. Tokushima, S. Wada, Y. Hayase, Tsuneo A. TakahashiAbstract:Long-term severe thrombocytopenia following human placental and umbilical cord blood (CB) transplantation is a significant clinical problem. We studied the ex vivo expansion of megakaryocytic progenitor cells (CFU-Meg) from cryopreserved/thawed leukocyte concentrates (LC) of CB prepared by the Tokyo Cord Blood Bank protocol. The LC cells were cultured in serum-free culture medium supplemented with a combination of early-acting cytokines including thrombopoietin (TPO), flt3-ligand (FL), and stem cell factor (SCF). Combination of TPO plus FL, TPO plus SCF, and all of these cytokines together resulted in 8.9-, 7.7-, and 8.4-fold increases in CFU-Meg, respectively, by Day 5 of culture. Our results showed that this simple expansion strategy has the potential for expanding CFU-Meg from cryopreserved/thawed LC cells from CB.
Martin J Murphy - One of the best experts on this subject based on the ideXlab platform.
-
Comparativein vitro myelotoxicity of FCE 24517, a distamycin derivative, to human, canine and murine hematopoietic progenitor cells
Investigational New Drugs, 1992Co-Authors: Donna A Volpe, De-lin Du, Maria Grazia Zurlo, Nicola Mongelli, Martin J MurphyAbstract:FCE 24517, a derivative of distamycin A, exhibits an unusual antitumor profile in experimental models. As part of its preclinical development, we evaluated the in vitro myelotoxicity of FCE 24517 to human, canine and murine hematopoietic cells. Marrow cells were exposed to the agent (2.7×10^−5−2.7 nM) for 4 h and then assayed in capillary (human) or Petri dish (canine, murine) clonal cultures. FCE 24517 inhibited myeloid (CFU-gm), erythroid (BFU-e, CFU-e) and megakaryocytic (CFU-Meg) colony formation in a concentration-dependent manner. The progenitor cells were generally similar in their response to FCE 24517 within a species. Comparing the different progenitor cell response to FCE 24517, canine CFU-gm and CFU-e were 26- to 221-fold more sensitive to this drug's toxic effects than their human and murine counterparts. This was demonstrated by extremely low IC_70 values for the canine CFU-gm (0.001 nM) and CFU-e (0.007 nM). Murine progenitors displayed 1.3- to 10.9-times higher IC_70 values than human CFU-gm, BFU-e and CFU-e following 4 hr exposure to FCE 24517. The data demonstrated that a mouse model may better predict human in vitro myelotoxicity to FCE 24517 than beagle dogs.
-
In vitro cloning of murine megakaryocyte progenitors (CFU-Meg)
Journal of tissue culture methods, 1991Co-Authors: Martin J Murphy, Kiyoyuki OgataAbstract:Convenient and reproducible culture systems for murine megakaryocyte progenitor cells (colony-forming unit-megakaryocytes, CFU-Meg) are described. Mouse bone marrow cells are cultured in fibrin clots supplemented with Iscove's modified Dulbecco's medium and fetal bovine serum or in fibrin clots supplemented with serum-free IMDM, bovine serum albumin, transferrin, cholesterol, and L- α -phosphatidylcholine. In the presence of murine interleukin-3 or pokeweed mitogen-stimulated murine spleen cell-conditioned medium, these cultures support CFU-Meg colony formation effectively. The cultivation and counting of colonies in these culture systems is considerably easier when compared with previously reported culture systems.
-
Comparative toxicity of fostriecin, hepsulfam and pyrazine diazohydroxide to human and murine hematopoietic progenitor cells in vitro
Investigational New Drugs, 1991Co-Authors: Donna A Volpe, Charles K. Grieshaber, Martin J MurphyAbstract:The in vitro myelotoxic potentials of three investigational antitumor agents, Fostriecin, Hepsulfam and pyrazine diazohydroxide (PZDH), were evaluated utilizing clonogenic assays. Human and murine marrow cells were exposed to each drug for 1 hr prior to culture in microcapillary (human) or Petri dish (murine) assays. Fostriecin (0.22–220 μM), Hepsulfam (0.34–340 μM) and PZDH (0.68–680 μM) inhibited myeloid (CFU-gm), erythroid (BFU-e, CFU-e) and megakaryocytic (CFU-Meg) colony formation in a concentration-dependent manner. CFU-e from both species were more sensitive to Fostriecin than the other progenitors and murine cells more sensitive overall to Fostriecin than their human counterparts. Murine CFU-e were also more sensitive to Hepsulfam than human CFU-e, with CFU-gm and BFU-e being similarly affected in both species. Human BFU-e were greatly inhibited by PZDH, whereas murine BFU-e were relatively resistant to its toxic effects. Fostriecin was the most toxic of the three antitumor agents, with PZDH the least toxic.
-
Purification of human megakaryocyte colony‐stimulating factor (Meg‐CSF) from urine of aplastic anemia patients
The International Journal of Cell Cloning, 1991Co-Authors: Connie L. Erickson-miller, Martin J Murphy, Ralph E. Parchment, Zhang Zhao-geng, W. Dai, S. G. Ling, P. H. TangAbstract:Our laboratory has already documented that extracts of urine from aplastic anemia patients stimulate megakaryocyte and platelet production in vivo in rats and mice. This stimulatory activity was apparently mediated by a unique cytokine. This report describes the purification of the factor likely responsible for this activity because it stimulates megakaryocyte colony formation (CFU-Meg) in vitro. The factor, when purified to homogeneity, exhibits a molecular weight of 55,000–57,000 and an isoelectric point of 7.2–7.4. Under physiological conditions, ultrafiltration experiments indicate that human megakaryocyte colony-stimulating factor (hMeg-CSF) exists as a monomer or dimer. In contrast to human urinary erythropoietin (Epo), only a small amount of hMeg-CSF forms complexes of high molecular weight aggregates. In contrast to interleukin (IL)-3, hMeg-CSF induces small colonies in vitro containing three to five megakaryoblasts. Even at concentrations 100-fold greater than the threshold amount required to stimulate CFU-Meg colony formation, hMeg-CSF stimulated only CFU-Meg colonies, but did not stimulate myeloid or erythroid lineage colonies. We propose that this purified factor is specific for the megakaryocyte lineage, and that it be termed human Meg-CSF.
Kathleen E. Rodgers - One of the best experts on this subject based on the ideXlab platform.
-
Angiotensin-(1–7) synergizes with colony-stimulating factors in hematopoietic recovery
Cancer Chemotherapy and Pharmacology, 2013Co-Authors: Kathleen E. Rodgers, Norma Roda, Theresa B. Espinoza, Christopher J. Meeks, Gere S. DizeregaAbstract:Purpose Angiotensin (1–7) [A(1–7)] is a bioactive peptide of the renin angiotensin system that stimulates the number of bone marrow progenitors and hematopoietic recovery after myelosuppression. We evaluated the combination of A(1–7) with colony-stimulating factors, Neupogen and Epogen, on bone marrow progenitors and the recovery of circulating formed elements following chemotherapy. Methods Mice were injected with gemcitabine followed 2 days later with A(1–7). Circulating blood cells and bone marrow progenitors were measured over time. Results Combination of A(1–7) with Neupogen (the latter given only 3 days starting at the white blood cell nadir) decreased the amount of Neupogen needed for optimal recovery by 10-fold. The progenitors measured include CFU-GEMM, CFU-GM, CFU-Meg and BFU-E. A(1–7) increased recovery of all progenitors when given alone or in combination with Neupogen above that with Neupogen alone. Combination of A(1–7) with Epogen slightly increased (not significantly) red blood cell concentrations above those achieved by Epogen alone. However, in this model, A(1–7) or A(1–7) in combination with Epogen increased all erythroid progenitors with the largest effect on early erythroid progenitors (immature BFU-E). Conclusions Neupogen and Epogen acted synergistically with A(1–7) to increase the concentration of myeloid, megakaryocytic and erythroid progenitor cells in the bone marrow following chemotherapy suggesting that A(1–7)’s multilineage effect on early progenitors in the marrow facilitates proliferation in response to lineage-specific growth factors.
-
Synergistic effects of co-administration of angiotensin 1–7 and Neupogen on hematopoietic recovery in mice
Cancer Chemotherapy and Pharmacology, 2004Co-Authors: Dolph D. Ellefson, Gere S. Dizerega, Theresa Espinoza, Norma Roda, Sonia Maldonado, Kathleen E. RodgersAbstract:Purpose Angiotensin 1–7 [A(1–7)] is a seven amino acid peptide that has been shown to increase the proliferation of epidermal stem cells after dermal injury and the number of hematopoietic progenitors in the bone marrow of myelosuppressed mice. In this study, the effect of combining A(1–7) with Neupogen on hematopoietic recovery and bone marrow progenitors was evaluated. Materials and methods Intravenous 5-fluorouracil (5FU) was administered to induce myelosuppression. Administration of A(1–7) and/or Neupogen was initiated 2 days after chemotherapy. Angiotensin II (AII) and A(1–7) binding were assessed by flow cytometric analysis. Hematopoietic progenitors were counted by colony forming assays. Recovery of formed elements in the blood was evaluated by hemocytometer. Results Flow cytometric analysis indicated that the number of early hematopoietic progenitors (Lin^−Sca1^+cKit^+) that bind AII or A(1–7) increased 5–7 days after intravenous injection of 150 mg/kg 5FU. Further, administration of A(1–7) led to a slight increase in the number of circulating leukocytes and platelets after this chemotherapeutic regimen. When given in combination with a subclinical dose of Neupogen, a synergistic effect on the number of circulating leukocytes was observed, but there was no further effect on the number of circulating platelets. In myelosuppressed mice, A(1–7) had its most profound effect on the number of hematopoietic progenitors in the bone marrow. The progenitors evaluated in the study included BFU-E, CFU-Meg, CFU-GM and CFU-GEMM. There was an increase in the number of these progenitors in the bone marrow, indicating an effect on all hematopoietic lineages. When given in combination with Neupogen, these effects were synergistic for the numbers of BFU-E and CFU-Meg (Neupogen by itself had no effect) and for the myeloid progenitors at lower doses of A(1–7). Conclusions These results suggest that these hematopoietic agents act at different sites within the hematopoietic cascade and that combining these two agents may be of benefit in the treatment of hematopoietic disorders.
-
Synergistic effects of co-administration of angiotensin 1–7 and Neupogen on hematopoietic recovery in mice
Cancer Chemotherapy and Pharmacology, 2004Co-Authors: Dolph D. Ellefson, Gere S. Dizerega, Theresa Espinoza, Norma Roda, Sonia Maldonado, Kathleen E. RodgersAbstract:Purpose : Angiotensin 1–7 [A(1–7)] is a seven amino acid peptide that has been shown to increase the proliferation of epidermal stem cells after dermal injury and the number of hematopoietic progenitors in the bone marrow of myelosuppressed mice. In this study, the effect of combining A(1–7) with Neupogen on hematopoietic recovery and bone marrow progenitors was evaluated. Materials and methods : Intravenous 5-fluorouracil (5FU) was administered to induce myelosuppression. Administration of A(1–7) and/or Neupogen was initiated 2 days after chemotherapy. Angiotensin II (AII) and A(1–7) binding were assessed by flow cytometric analysis. Hematopoietic progenitors were counted by colony forming assays. Recovery of formed elements in the blood was evaluated by hemocytometer. Results : Flow cytometric analysis indicated that the number of early hematopoietic progenitors (Lin^−Scal^+cKit^+) that bind AII or A(1–7) incrased 5–7 days after intravenous injection of 150 mg/kg 5FU. Further, administration of A(1–7) led to a slight increase in the number of circulating leukocytes and platelets after this chemotherapeutic regimen. When given in combination with a subclinical dose of Neupogen, a synergistic effect on the number of ciruclating leukocytes was observed, but there was no further effect on the number of circulating platelets. In myelosuppressed mice, A(1–7) had its most profound effect on the number of hematopoietic progenitors in the bone marrow. The progenitors evaluated in the study included BFU-E, CFU-Meg, CFU-GM and CFU-GEMM. There was an increase in the number of these progenitors in the bone marrow, indicating an effect on all hematopoietic lineages. When given in combination with Neupogen, these effects were synergistic for the numbers of BFU-E and CFU-Meg (Neupogen by itself had no effect) and for the myeloid progenitors at lower doses of A(1–7). Conclusions : These results suggest that these hematopoietic agents act at different sites within the hematopoietic cascade and that combining these two agents may be of benefit in the treatment of hematopoietic disorders.